1. Field of the Invention
The present invention pertains to shipping cartons having containers with removable covers, and in particular to containers for food products.
2. Description of the Related Art
Food products and other commercially important goods have been packaged in cup or tub-like containers, as shown, for example, in U.S. Pat. Nos. 3,166,190 and 3,409,124; 4,932,531 and 3,828,926. Typically, the tub containers are of similar size and are arranged in a two dimensional array, being supported so as to lie in a common plane. In some arrangements, a paperboard sleeve or outer wrapper encircles the array of tub containers so as to hold them in position. Due to the wrapper construction, the ends of the container assemblies are usually left open, relying on the ability of the tub containers to preserve the product in its desired condition. Arrangements are also provided to make use of the tub lids or other outward protuberances to "hook" the tubs together at their upper ends, further decreasing the amount of protective overwrap. Typically, the above arrangements are provided for shipping of a single layer of tub containers.
When multiple layers or tiers of tub containers are required, an intermediate wall of paperboard material is typically disposed between the tiers. The intermediate wall may be provided in conjunction with a paperboard wrapper encircling both tiers of tub containers, as shown in U.S. Pat. Nos. 4,756,419 and 4,932,531. In one arrangement, shown in U.S. Pat. No. 4,319,680, an outer carton housing in the form of a sleeve holds multiple tiers of single row individual product units, such as display packs or blister packs having outwardly extending flanges. The carton housing receives the flanges holding them, and hence the product units, in a single stack spaced-apart relation.
Despite these developments, further improvements in food product packaging are being sought.